On-Line Analysis of the Heterogeneous Pd-Catalyzed Transfer Hydrogenation of p-Nitrophenol in Water with Formic Acid in a Flow Reactor

Rhodium-terpyridine Catalyzed Transfer Hydrogenation of Aromatic Nitro Compounds in Water

A rhodium terpyridine complex catalyzed transfer hydrogenation of nitroarenes to anilines with i-PrOH as hydrogen source and water as solvent has been developed. The catalytic system can work at a substrate/catalyst (S/C) ratio of 2000, with a turnover frequency (TOF) up to 3360 h^-1 , which represents one of the most active catalytic transfer hydrogenation systems for nitroarene reduction. The catalytic system is operationally simple and the protocol could be scaled up to 20 gram scale. The water-soluble catalyst bearing a carboxyl group could be recycled 15 times without significant loss of activity.

Electrochemical detection of organophosphorus pesticides based on amino acids-conjugated P3TAA-modified electrodes

In this work, amino acids (AAs) including serine (S), histidine (H) and glutamic acid (E)-conjugated poly(3-thiophene acetate acid) (P3TAA) were synthesized to promote the catalytic hydrolysis and in situ electrochemical detection of organophosphorus pesticides (OPs). The hydrolysis of OPs followed the mechanism of proton transfer relay composed of AAs of S, H, E, called the "catalytic triad", found in biomimetic hydrolases. P3TAA was used as a carrier to attach S, H, E, and these AA sites have the hydrolysis activity of Ops; the polymer P3TAA-AAs behaved like biomimetic enzymes. After the hydrolysis of OPs (e.g., methyl paraoxon, ethyl paraoxon and methyl parathion), p-nitrophenol (PNP) was generated, which can be detected electrochemically. Herein, an electrochemical method using P3TAA-conjugated S, H, E-modified electrodes for the determination of OPs was developed. OPs can be quantified by the electrochemical responses of PNP. This technique was selective toward OPs with the p-nitrophenol group. The detection limit of OPs (methyl paraoxon, methyl parathion and ethyl paraoxon) reached 0.5 μM. This detection technique was successfully applied to the detection of OPs in real samples with high detection accuracy.